Unblemished white teeth have long been considered cosmetically desirable. Unfortunately, in the absence of thorough dental cleaning, teeth can become discolored or stained from color-causing substances present in food, beverages, tobacco, and the like, and internal sources such as blood, amalgam-based fillings, and antibiotics (e.g., tetracycline). The tooth structures that are generally responsible for presenting a stained appearance are enamel, dentin, and the acquired pellicle. Tooth enamel is predominantly formed from inorganic material, mostly in the form of hydroxyapatite crystals, and further contains approximately 5% organic material primarily in the form of collagen. In contrast, dentin is composed of about 20% protein including collagen, the balance consisting of inorganic material, predominantly hydroxyapatite crystals, similar to that found in enamel. The acquired pellicle is a proteinaceous layer or matrix that forms continuously over the surface of the tooth. Although the acquired pellicle can be removed through intensive mechanical cleaning, it quickly regenerates soon thereafter.
Discoloration of teeth can result from intrinsic and/or extrinsic staining. Intrinsic staining occurs when staining compounds penetrate the enamel and even the dentin, or alternatively, such staining arises from sources within the tooth. Typically such staining can only be removed through chemical methods of tooth cleaning. In contrast, extrinsic staining of the acquired pellicle arises as a result of compounds such as tannins and other polyphenolic compounds becoming trapped in and tightly bound to the proteinaceous layer on the surface of teeth. Discoloration from this type of staining can usually be removed by mechanical methods of tooth cleaning.
Stain removing agents have been used to remove such staining to whiten and clean teeth. One class of effective stain removing agents includes surfactants such as, for example, sodium stearate, which have been found to exhibit good stain removing activity on teeth. Such stain removing agents have been incorporated into stain removing chewing gum and confectionery compositions to clean and whiten teeth as disclosed in U.S. Pat. Nos. 6,471,945, 6,479,071 and 6,485,739. Other classes of stain removing agents include, for example, anti-bacterial agents such as thymol, triclosan, chlorhexidine and the like.
Although some surfactants and anti-bacterial agents which are slightly water soluble act effectively as stain removing agents, the limited solubility of such agents in water or aqueous environments adversely affects their ability to be delivered from the stain removing composition to the tooth surfaces in the mouth. This shortcoming is especially apparent in chewing gum compositions. Further, these surfactants and anti-bacterial agents do not effectively penetrate through the complex barriers typically present in saliva and on the tooth surfaces, thus further reducing their bioavailability for removing stain. Accordingly, higher levels of surfactants or anti-bacterial agents are typically needed to compensate their low release rate, and increase their bioavailability in the mouth of the consumer.
Higher levels of surfactant and/or anti-bacterial agent in stain removing compositions increase manufacturing costs with little improvement to whitening or stain removing efficacy of the composition. In addition, it has been determined that stain removing compositions containing higher levels of surfactant or anti-bacterial agent typically exhibit less than desirable organoleptic and taste characteristics. For example, chewing gum and confectionery compositions containing elevated levels of surfactant typically exhibit a soapy or undesirable taste, and unpleasant mouthfeel. In chewing gum, the elevated levels of surfactant also adversely affect the structure of the gum base resulting in premature disintegration, and unsatisfactory chew characteristics.
Cyclodextrin compounds are known to form complexes with many compounds. The cyclodextrin molecule includes glucopyranose units arranged in a ring-like configuration having all the secondary hydroxyl groups located on one side of the ring and all primary hydroxyl groups located on the other side. Generally, ′Y-, β-, and ε-cyclodextrins contain 6, 7 and 8 cyclic glucopyranose units, respectively, in the ring shell. The lining of the internal “cavity” is formed from hydrogen and glucosidic oxygen-bridge atoms, and thus the lining is slightly apolar.
It would therefore be a significant advance in the art of providing a stain removing chewing gum composition, which enhances the overall solubility and release rate of a stain removing agent therefrom. It would be a further advance in the art to provide a stain removing chewing gum composition which enhances the solubility and the release rate of the stain removing agent through the use of a complex of a stain removing agent and a cyclodextrin compound. The complex provides effective cleaning of dental material including teeth and can be effectively incorporated into a chewing gum composition and released therefrom during the chewing process in a manner which provides an effective amount of the stain removing agent. The chewing gum composition would then not only provide chewing satisfaction to the user, but would also provide a beneficial dental effect. There is a need for a chewing gum composition having enhanced tooth whitening and stain removal efficacy while avoiding or at least substantially minimizing the consequences of the above-described problems encountered in the prior art.
Confectionery compositions are well known in the art. Such compositions include, for example, hard boiled candies, nougats, panning goods, gel confections, centerfill confections, fondants, consumable thin films, and the like. Unlike chewing gum compositions, which often remain in the mouth for up to or exceeding several minutes, confectionery compositions tend to have a short life in the mouth because they dissolve relatively quickly upon chewing. Nonetheless, it would be of great benefit to provide confectionery compositions with an effective amount of a stain removing agent to provide such products to render them capable of providing a beneficial dental effect.